netconf/sal-netconf-connector/src/main/java/org/opendaylight/netconf/sal/connect/netconf/sal/KeepaliveSalFacade.java

   1 /*
   2  * Copyright (c) 2015 Cisco Systems, Inc. and others.  All rights reserved.
   3  *
   4  * This program and the accompanying materials are made available under the
   5  * terms of the Eclipse Public License v1.0 which accompanies this distribution,
   6  * and is available at http://www.eclipse.org/legal/epl-v10.html
   7  */
   8 package org.opendaylight.netconf.sal.connect.netconf.sal;
   9
  10 import static org.opendaylight.netconf.sal.connect.netconf.util.NetconfBaseOps.getSourceNode;
  11 import static org.opendaylight.netconf.sal.connect.netconf.util.NetconfMessageTransformUtil.NETCONF_GET_CONFIG_QNAME;
  12 import static org.opendaylight.netconf.sal.connect.netconf.util.NetconfMessageTransformUtil.NETCONF_RUNNING_QNAME;
  13 import static org.opendaylight.netconf.sal.connect.netconf.util.NetconfMessageTransformUtil.toPath;
  14
  15 import com.google.common.base.Preconditions;
  16 import com.google.common.util.concurrent.CheckedFuture;
  17 import com.google.common.util.concurrent.FutureCallback;
  18 import com.google.common.util.concurrent.Futures;
  19 import java.util.concurrent.ScheduledExecutorService;
  20 import java.util.concurrent.ScheduledFuture;
  21 import java.util.concurrent.TimeUnit;
  22 import javax.annotation.Nonnull;
  23 import javax.annotation.Nullable;
  24 import org.opendaylight.controller.md.sal.dom.api.DOMNotification;
  25 import org.opendaylight.controller.md.sal.dom.api.DOMRpcAvailabilityListener;
  26 import org.opendaylight.controller.md.sal.dom.api.DOMRpcException;
  27 import org.opendaylight.controller.md.sal.dom.api.DOMRpcResult;
  28 import org.opendaylight.controller.md.sal.dom.api.DOMRpcService;
  29 import org.opendaylight.netconf.sal.connect.api.RemoteDeviceHandler;
  30 import org.opendaylight.netconf.sal.connect.netconf.listener.NetconfDeviceCommunicator;
  31 import org.opendaylight.netconf.sal.connect.netconf.listener.NetconfSessionPreferences;
  32 import org.opendaylight.netconf.sal.connect.netconf.util.NetconfMessageTransformUtil;
  33 import org.opendaylight.netconf.sal.connect.util.RemoteDeviceId;
  34 import org.opendaylight.yangtools.concepts.ListenerRegistration;
  35 import org.opendaylight.yangtools.yang.data.api.schema.ContainerNode;
  36 import org.opendaylight.yangtools.yang.data.api.schema.NormalizedNode;
  37 import org.opendaylight.yangtools.yang.model.api.SchemaContext;
  38 import org.opendaylight.yangtools.yang.model.api.SchemaPath;
  39 import org.slf4j.Logger;
  40 import org.slf4j.LoggerFactory;
  41
  42 /**
  43  * SalFacade proxy that invokes keepalive RPCs to prevent session shutdown from remote device
  44  * and to detect incorrect session drops (netconf session is inactive, but TCP/SSH connection is still present).
  45  * The keepalive RPC is a get-config with empty filter.
  46  */
  47 public final class KeepaliveSalFacade implements RemoteDeviceHandler<NetconfSessionPreferences> {
  48
  49     private static final Logger LOG = LoggerFactory.getLogger(KeepaliveSalFacade.class);
  50
  51     // 2 minutes keepalive delay by default
  52     private static final long DEFAULT_DELAY = TimeUnit.MINUTES.toSeconds(2);
  53
  54     // 1 minute transaction timeout by default
  55     private static final long DEFAULT_TRANSACTION_TIMEOUT_MILLI = TimeUnit.MILLISECONDS.toMillis(60000);
  56
  57     private final RemoteDeviceId id;
  58     private final RemoteDeviceHandler<NetconfSessionPreferences> salFacade;
  59     private final ScheduledExecutorService executor;
  60     private final long keepaliveDelaySeconds;
  61     private final ResetKeepalive resetKeepaliveTask;
  62     private final long defaultRequestTimeoutMillis;
  63
  64     private volatile NetconfDeviceCommunicator listener;
  65     private volatile ScheduledFuture<?> currentKeepalive;
  66     private volatile DOMRpcService currentDeviceRpc;
  67
  68     public KeepaliveSalFacade(final RemoteDeviceId id, final RemoteDeviceHandler<NetconfSessionPreferences> salFacade,
  69                               final ScheduledExecutorService executor, final long keepaliveDelaySeconds,
  70                               final long defaultRequestTimeoutMillis) {
  71         this.id = id;
  72         this.salFacade = salFacade;
  73         this.executor = executor;
  74         this.keepaliveDelaySeconds = keepaliveDelaySeconds;
  75         this.defaultRequestTimeoutMillis = defaultRequestTimeoutMillis;
  76         this.resetKeepaliveTask = new ResetKeepalive();
  77     }
  78
  79     public KeepaliveSalFacade(final RemoteDeviceId id, final RemoteDeviceHandler<NetconfSessionPreferences> salFacade,
  80                               final ScheduledExecutorService executor) {
  81         this(id, salFacade, executor, DEFAULT_DELAY, DEFAULT_TRANSACTION_TIMEOUT_MILLI);
  82     }
  83
  84     /**
  85      * Set the netconf session listener whenever ready.
  86      *
  87      * @param listener netconf session listener
  88      */
  89     public void setListener(final NetconfDeviceCommunicator listener) {
  90         this.listener = listener;
  91     }
  92
  93     /**
  94      * Just cancel current keepalive task.
  95      * If its already started, let it finish ... not such a big deal.
  96      *
  97      * <p>
  98      * Then schedule next keepalive.
  99      */
 100     void resetKeepalive() {
 101         LOG.trace("{}: Resetting netconf keepalive timer", id);
 102         if (currentKeepalive != null) {
 103             currentKeepalive.cancel(false);
 104         }
 105         scheduleKeepalive();
 106     }
 107
 108     /**
 109      * Cancel current keepalive and also reset current deviceRpc.
 110      */
 111     private void stopKeepalives() {
 112         if (currentKeepalive != null) {
 113             currentKeepalive.cancel(false);
 114         }
 115         currentDeviceRpc = null;
 116     }
 117
 118     void reconnect() {
 119         Preconditions.checkState(listener != null, "%s: Unable to reconnect, session listener is missing", id);
 120         stopKeepalives();
 121         LOG.info("{}: Reconnecting inactive netconf session", id);
 122         listener.disconnect();
 123     }
 124
 125     @Override
 126     public void onDeviceConnected(final SchemaContext remoteSchemaContext,
 127                           final NetconfSessionPreferences netconfSessionPreferences, final DOMRpcService deviceRpc) {
 128         this.currentDeviceRpc = deviceRpc;
 129         final DOMRpcService deviceRpc1 =
 130                 new KeepaliveDOMRpcService(deviceRpc, resetKeepaliveTask, defaultRequestTimeoutMillis, executor);
 131         salFacade.onDeviceConnected(remoteSchemaContext, netconfSessionPreferences, deviceRpc1);
 132
 133         LOG.debug("{}: Netconf session initiated, starting keepalives", id);
 134         scheduleKeepalive();
 135     }
 136
 137     private void scheduleKeepalive() {
 138         Preconditions.checkState(currentDeviceRpc != null);
 139         LOG.trace("{}: Scheduling next keepalive in {} {}", id, keepaliveDelaySeconds, TimeUnit.SECONDS);
 140         currentKeepalive = executor.schedule(new Keepalive(currentKeepalive), keepaliveDelaySeconds, TimeUnit.SECONDS);
 141     }
 142
 143     @Override
 144     public void onDeviceDisconnected() {
 145         stopKeepalives();
 146         salFacade.onDeviceDisconnected();
 147     }
 148
 149     @Override
 150     public void onDeviceFailed(final Throwable throwable) {
 151         stopKeepalives();
 152         salFacade.onDeviceFailed(throwable);
 153     }
 154
 155     @Override
 156     public void onNotification(final DOMNotification domNotification) {
 157         resetKeepalive();
 158         salFacade.onNotification(domNotification);
 159     }
 160
 161     @Override
 162     public void close() {
 163         stopKeepalives();
 164         salFacade.close();
 165     }
 166
 167     // Keepalive RPC static resources
 168     private static final SchemaPath PATH = toPath(NETCONF_GET_CONFIG_QNAME);
 169     private static final ContainerNode KEEPALIVE_PAYLOAD = NetconfMessageTransformUtil.wrap(NETCONF_GET_CONFIG_QNAME,
 170             getSourceNode(NETCONF_RUNNING_QNAME), NetconfMessageTransformUtil.EMPTY_FILTER);
 171
 172     /**
 173      * Invoke keepalive RPC and check the response. In case of any received response the keepalive
 174      * is considered successful and schedules next keepalive with a fixed delay. If the response is unsuccessful (no
 175      * response received, or the rcp could not even be sent) immediate reconnect is triggered as netconf session
 176      * is considered inactive/failed.
 177      */
 178     private class Keepalive implements Runnable, FutureCallback<DOMRpcResult> {
 179
 180         private final ScheduledFuture<?> previousKeepalive;
 181
 182         Keepalive(final ScheduledFuture<?> previousKeepalive) {
 183             this.previousKeepalive = previousKeepalive;
 184         }
 185
 186         @Override
 187         public void run() {
 188             LOG.trace("{}: Invoking keepalive RPC", id);
 189
 190             try {
 191                 if (previousKeepalive != null && !previousKeepalive.isDone()) {
 192                     onFailure(new IllegalStateException("Previous keepalive timed out"));
 193                 } else {
 194                     Futures.addCallback(currentDeviceRpc.invokeRpc(PATH, KEEPALIVE_PAYLOAD), this);
 195                 }
 196             } catch (NullPointerException e) {
 197                 LOG.debug("{}: Skipping keepalive while reconnecting", id);
 198                 // Empty catch block intentional
 199                 // Do nothing. The currentDeviceRpc was null and it means we hit the reconnect window and
 200                 // attempted to send keepalive while we were reconnecting. Next keepalive will be scheduled
 201                 // after reconnect so no action necessary here.
 202             }
 203         }
 204
 205         @Override
 206         public void onSuccess(final DOMRpcResult result) {
 207             if (result != null && result.getResult() != null) {
 208                 LOG.debug("{}: Keepalive RPC successful with response: {}", id, result.getResult());
 209                 scheduleKeepalive();
 210             } else {
 211                 LOG.warn("{} Keepalive RPC returned null with response: {}. Reconnecting netconf session", id, result);
 212                 reconnect();
 213             }
 214         }
 215
 216         @Override
 217         public void onFailure(@Nonnull final Throwable throwable) {
 218             LOG.warn("{}: Keepalive RPC failed. Reconnecting netconf session.", id, throwable);
 219             reconnect();
 220         }
 221     }
 222
 223     /**
 224      * Reset keepalive after each RPC response received.
 225      */
 226     private class ResetKeepalive implements FutureCallback<DOMRpcResult> {
 227         @Override
 228         public void onSuccess(@Nullable final DOMRpcResult result) {
 229             // No matter what response we got,
 230             // rpc-reply or rpc-error, we got it from device so the netconf session is OK.
 231             resetKeepalive();
 232         }
 233
 234         @Override
 235         public void onFailure(@Nonnull final Throwable throwable) {
 236             // User/Application RPC failed (The RPC did not reach the remote device or ..
 237             // TODO what other reasons could cause this ?)
 238             // There is no point in keeping this session. Reconnect.
 239             LOG.warn("{}: Rpc failure detected. Reconnecting netconf session", id, throwable);
 240             reconnect();
 241         }
 242     }
 243
 244     /*
 245      * Request timeout task is called once the defaultRequestTimeoutMillis is
 246      * reached. At this moment, if the request is not yet finished, we cancel
 247      * it.
 248      */
 249     private static final class RequestTimeoutTask implements Runnable {
 250
 251         private final CheckedFuture<DOMRpcResult, DOMRpcException> rpcResultFuture;
 252
 253         RequestTimeoutTask(final CheckedFuture<DOMRpcResult, DOMRpcException> rpcResultFuture) {
 254             this.rpcResultFuture = rpcResultFuture;
 255         }
 256
 257         @Override
 258         public void run() {
 259             if (!rpcResultFuture.isDone()) {
 260                 rpcResultFuture.cancel(true);
 261             }
 262         }
 263     }
 264
 265     /**
 266      * DOMRpcService proxy that attaches reset-keepalive-task and schedule
 267      * request-timeout-task to each RPC invocation.
 268      */
 269     public static final class KeepaliveDOMRpcService implements DOMRpcService {
 270
 271         private final DOMRpcService deviceRpc;
 272         private ResetKeepalive resetKeepaliveTask;
 273         private final long defaultRequestTimeoutMillis;
 274         private final ScheduledExecutorService executor;
 275
 276         KeepaliveDOMRpcService(final DOMRpcService deviceRpc, final ResetKeepalive resetKeepaliveTask,
 277                 final long defaultRequestTimeoutMillis, final ScheduledExecutorService executor) {
 278             this.deviceRpc = deviceRpc;
 279             this.resetKeepaliveTask = resetKeepaliveTask;
 280             this.defaultRequestTimeoutMillis = defaultRequestTimeoutMillis;
 281             this.executor = executor;
 282         }
 283
 284         public DOMRpcService getDeviceRpc() {
 285             return deviceRpc;
 286         }
 287
 288         @Nonnull
 289         @Override
 290         public CheckedFuture<DOMRpcResult, DOMRpcException> invokeRpc(@Nonnull final SchemaPath type,
 291                                                                       final NormalizedNode<?, ?> input) {
 292             final CheckedFuture<DOMRpcResult, DOMRpcException> domRpcResultDOMRpcExceptionCheckedFuture =
 293                     deviceRpc.invokeRpc(type, input);
 294             Futures.addCallback(domRpcResultDOMRpcExceptionCheckedFuture, resetKeepaliveTask);
 295
 296             final RequestTimeoutTask timeoutTask = new RequestTimeoutTask(domRpcResultDOMRpcExceptionCheckedFuture);
 297             executor.schedule(timeoutTask, defaultRequestTimeoutMillis, TimeUnit.MILLISECONDS);
 298
 299             return domRpcResultDOMRpcExceptionCheckedFuture;
 300         }
 301
 302         @Override
 303         public <T extends DOMRpcAvailabilityListener> ListenerRegistration<T> registerRpcListener(
 304                 @Nonnull final T listener) {
 305             // There is no real communication with the device (yet), no reset here
 306             return deviceRpc.registerRpcListener(listener);
 307         }
 308     }
 309 }